The therapeutic use of thermal blankets having walls of flexible polymeric material that are sealed together to define a labyrinth of passages for the circulation of heating or cooling fluid is well known. While such therapy may involve either heating or cooling portions of the body, it is the cooling mode that in recent years has received particular attention because of its effectiveness in post-operative treatment and in connection with physical therapy. In particular, cryotherapy following soft tissue trauma has been shown to reduce pain, swelling, blood loss, inflammation and hematoma formation. During the rehabilitative process, cryotherapy has been utilized effectively to diminish inflammation and patient discomfort.
For such therapy, the thermal blanket should fit snugly about and uniformly contact the area of the body requiring treatment. Where the treatment site is relatively flat, or is of regular contour, these objectives may be accomplished with a blanket that normally lies flat and can be placed against, or wrapped about, the body part. However, such objectives are far more difficult to achieve when the body portion to receive thermal treatment is a joint area of complex and variable curvatures such as the shoulder, elbow, ankle or knee. In such a case, the inability of a flat blanket to assume double curvatures and follow complex body contours may seriously compromise the effectiveness of the intended treatment. An alternative approach, that of providing a pre-formed non-planar blanket sized and shaped to match the contour of the treatment site, is considered impractical for a number of reasons including manufacturing complexities and cost.
The problems of providing effective cryotherapy (or heat therapy) to a joint area using a blanket having fluid circulation passages are further complicated by the difficulties of insuring proper flow throughout the blanket when it has been folded or wrapped about the treatment site. If, for example, the blanket is of a type that allows thermal fluid to flow at random because the thermoplastic layers are joined together at a multiplicity of points that do not provide clearly-defined flow routes, then, when such a blanket is wrapped or folded about the treatment site, the thermal fluid can be expected to take the paths of least resistance and certain areas of the blanket may receive little or no fluid circulation. On the other hand, if the blanket is of a type that has defined (i.e., tubular) flow passages, there is a risk that such passages may become kinked and obstruct fluid flow when the blanket is folded or wrapped about the treatment site.
All such blankets that provide for the circulation of thermal fluid have inlet and outlet tubes leading to and from the cooling/heating/pumping equipment that controls fluid temperature and directs flow circulation. Such tubes, and the inlet and outlet passages of the blanket with which they communicate, are vulnerable to kinking, twisting, and flow obstruction as a patient moves about or changes body position during waking hours and, in particular, during sleep, when such obstruction of the passages may go unnoticed.
Accordingly, an important aspect of this invention lies in providing a blanket that is particularly suitable for the thermal treatment of joint areas and may be easily adjusted to fit patients of different size and physical characteristics notwithstanding the fact that the blanket is manufactured (and may be marketed and stored) in substantially flat or planar condition. A zigzag arrangement of dual passages extends through the blanket in directions that eliminate or greatly reduce possibilities of partial or total flow obstruction since, by reason of such arrangement, forces imposed on the passages when the blanket is properly folded or wrapped over a treatment site tend to be in the form of twisting rather than kinking forces. Kinking of inlet and outlet tubes and the inlet/outlet passages of the blanket with which they communicate is prevented by providing the blanket with an integral limb wrap that supports the tubes and the fluid coupling element(s) connected to them and immobilizes such tubes and element(s) in relation to the patient's limb. Close fitting of the blanket to the treatment site is assured by providing the planar blanket with an outline of distinctive and developed shape, by utilizing Velcro-type hook and loop attachment means, and by providing substantially the entire outer (exterior) panel of the blanket with a soft loop-providing pile fabric which constitutes the loop component of the hook-loop attachment system.
Briefly, the blanket includes a foldable bodyside panel composed of double layers of thermoplastic sheet material heat-sealed together to define at least one, and preferably two, serpentine flow passages extending along zigzag pathways from an inlet opening to an adjacent outlet opening. The blanket also includes a soft, foldable exterior panel covering the entire bodyside panel with the peripheral edges of the two panels being secured together. As stated, the entire exterior surface of the blanket is composed of a loop-providing pile fabric and at least one of the main sections of the distinctively shaped planar blanket is provided with a hook-providing attachment patch which is releasably attachable to the loop-providing exterior panel in a manner that assures a snug fit over or about the area of treatment.
The integral limb-attaching means takes the form of a T-shaped section having a central strap portion terminating in an elongated limb-wrapping band portion. The parallel and flexible inlet and outlet tubes extend along the strap portion with each tube being connected at one end to an inlet or outlet opening of the blanket and at its opposite end to a fluid coupling element that overlies the exterior surface of the T-shaped section for easy access during a coupling/uncoupling operation while, at the same time, preventing twisting and kinking of the tubes and cushioning the limb from direct contact with the coupling element.
When the blanket is configured for thermal treatment of a shoulder joint, it has a generally C-shaped outline that defines two main sections, one of which is intended to be folded over the top of the shoulder and the other about the shoulder's side (or uppermost arm) surface. A free edge of the second section is adjustably connected to the first section in partial overlapping relation by means of the hook-providing attachment patch which, preferably, is elastically stretchable in directions towards and away from that free edge. The shoulder blanket also includes flap portions which cover portions of the back and chest of the wearer and are adjustably connected by a body strap which extends about the wearer's body below the shoulder and arm opposite from the shoulder receiving thermal treatment. Additional means in the form of resilient foam pads and closure flaps insure close conformity of the blanket with the shoulder and promote more efficient and uniform thermal exchange. Because of its distinctive configuration, the shoulder blanket is adapted to cover either the patient's right or left shoulder with the same ease of application for achieving a close fit for efficient and effective therapy.
Other features, advantages and objects will appears from the specification and drawings.